A mixed reality (MR) system provides, to the user, a combined image obtained by combining a physical space image and a virtual space image generated according to the viewpoint position, the line of sight direction, and the like of the user (see Japanese Patent Laid-Open No. 2002-159019). The MR system can present a virtual object to the observer as if it were existing on a physical space, and allows the observer to make an observation with a sense of actual dimensions and higher reality than a conventional virtual reality (VR) system.
On the other hand, as a conventional method of verifying the operability, maintainability, and assembling ability of objects designed by three-dimensional CAD in the design and manufacture fields, a method of manipulating a hand as a virtual object displayed on the virtual space using a hand as physical objects to allow the user to touch, manipulate, and verify, by his or her hand, a prototype object as if that object were existing there.
For this purpose, the position, orientation, and enlargement scale of the virtual object must be corrected to match the hand as the physical object.
However, in order to accurately calibrate the hand as the physical object and that as the virtual object in the above system, there are many correction parameters such as the overall size, the width and height of the palm, the lengths of fingers, and the like. Upon calibration of an object which has a complicated and flexible shape like the hand, deformations of the hand shape must be coped with. Normally, a method of correcting the enlargement scale by designating all feature points required to correct the enlargement magnification using a device such as a mouse, three-dimensional pointing device, or the like that can designate arbitrary points on the space is used. However, this method requires long calibration time, thus impairing the interfacing of the system.
When the above verification system is used by a plurality of operators, and when the operator changes, the hand as the physical object also changes. Therefore, calibration must be done frequently, thus bottlenecking easiness and speeding up of calibration.
When calibration must be frequently done for an object with a complicated and flexible shape like the hand as the physical object, a method of performing easy calibration between the physical object and virtual object at high speed is demanded.